(Latin) Literally "Not Worth a Rat's Ass," the slogan of the Tunnel Rats, who were either U.S. Army combat engineers or infantrymen of small stature who cleared the extensive tunnel network of the Viet Cong during the Vietnam War.

Willy wore a patch with the saying "Non Gratum Anus Rodentum" on his field jacket. This indicates that he was a Tunnel Rat during 'Nam.